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1 1. Characteristics of the Medium 2. Jet-medium interactions Extraction of jet functions 3. Summary of few things learned “Any man who knows all the answers most likely misunderstood the questions” Nancy Willard
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Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 20092 Gold nucleus Gold nucleus v~0.99c z:collision axis t 0 t = z/c t = -z/c “Thermalized” partonic Fluid! (s)QGP? Bjorken ~ 5 - 15 GeV/fm 3 ~ 35 – 100 ε 0 A “little Bang” occurs in RHIC collisions How do we probe the properties this fluid?
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3 u Extraction of transport coefficients (η/s, q, c s, λ, etc) can lend decisive insight Accurate measurements are crucial! Correlation measurements Flow Correlations Jet Correlations Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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4 The case is now closed on issues of non-flow etc, via 5 separate measurements of v 2 and v 4 in the same experiment The non-flow “chicken” has come home to roost The non-flow “chicken” has come home to roost New RXN detector Event planes PHENIX Preliminary Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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5 KE T – CQN Scaling Phys. Rev. Lett. 98, 162301 (2007) Mesons Baryons Quark-Like Degrees of Freedom Evident Indication of strong coupling? Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009 Arguments which say that quark degrees of freedom can not be present are silly!
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6 KE T & n q 2 scaling validated for v 4 KE T and CQN Scaling for v 4 PHENIX Preliminary Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009 Further Indication of strong coupling?
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7 Hints? 1.Hadronization? 2. Partonic Thermalization? Is this an indication that the partonic fluid is thermalized? a Related to η/s ? Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009 V n is universal Further Indication of strong coupling?
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PHENIX Preliminary 8 Straightforward estimation of the degree of local equilibrium and η/s as a function of centrality! 10-15% larger than for fluid with η/s =1/4π in central events. λ = 0.3 – 0.35 Better constrained estimates of coefficients
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9 x10 x20 QCD Sonic Boom Same-Side Jet High pT trigger Gives sound speed directly; Sets upper limit on viscosity. Medium Response & Transport Coefficients Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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10 2P & 3P correlation measurements? Strategy Compare jet correlations in pp & AA Collisions AB B It is necessary to decompose flow and Jet correlations Jet function ZYAM Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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11 There are three methods to gaining wisdom. The first is reflection, which is the highest. The second is limitation, which is the easiest. The third is experience, which is the bitterest.” Confucius Reflection Based on a two source model Two source models with similar Input same result. Jets correlate [or/not] with event plane Flow contributions dominate Accurate determination of v2 required Jet function (shape) is insensitive to ZYAM assumption The “’wisdom” of ZYAM! Limitations Uncertainty in jet yields Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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12 Same-Side Jet Away-Side Jet High pT trigger Assoc. pTs (2+1) processes efficiently removed via two-event mixing to obtain true three particle correlations Deflected jetMach Cone Validation test of the use of two event mixing to remove 2+1 processes Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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13 Di-jet correlation measurements? AB B A B Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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14 Medium Response Modified Away-side topology is p T independent Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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15 Medium Response “Particle composition” Composition of away-side jet similar to inclusive measurement Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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16 Data Simulated Deflected jet Simulated Mach Cone Data compatible with the presence of a Mach Cone away-side jet Total 3PC jet correlations True 3PC jet correlations QCD Sonic Boom? Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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17 simul Jet Suppression Simultaneous fits to I AA and R AA provide improved constraints Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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18 A central goal of current relativistic heavy ion research is the extraction of the transport properties of the recently discovered sQGP. Correlation measurements provide important constraints for a number of these properties Scattering power Scattering power Sound speed Sound speed Sound attenuation Sound attenuation viscosity viscosity etc. etc. Summary Roy A. Lacey, Stony Brook University; CATHIE-RIKEN Workshop, BNL Feb 25 - 26, 2009
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